converters/libiconv:
- Remove const qualifier from iconv(3) to match POSIX:
http://pubs.opengroup.org/onlinepubs/9699919799/functions/iconv.html
- Patch iconv.h to expose more GNU extensions when LIBICONV_PLUG is
defined because the base system iconv supports these extensions too.
Add/remove patches to/from ports to call iconv with non-const arguments.
This breaks some ports on FreeBSD 10 because base system iconv.h still has
the const qualifier. Fix this by letting USES=iconv add a build dependency
on converters/libiconv so ports can use its iconv.h (with LIBICONV_PLUG
defined) instead of the base system iconv.h.
This exposed some ports that link with libiconv when it is available instead
of using libc iconv. In these cases one of the following changes has been

- Unbreak parallel (-jX) builds: add missing inter-source dependencies
- Drop leading indefinite article from the COMMENT
- Add missing HEIMDAL_DESC, use new syntax for LIB_DEPENDS
- Improve the order of the knobs within the Makefile

This is an enterprise-class instant messaging/notification system.
It was developed as part of MIT's Project Athena, and has a
unique design that leads to the ability to develop a unique
sense of community.
WWW: http://zephyr.1ts.org/
PR: ports/141790
Submitted by: Ben Kaduk <kaduk at mit.edu>